Tailoring surface wetting states for ultrafast solar-driven water evaporation

Abstract

Tuning surface wettability can modulate the escape behaviour of water molecules to accelerate solar water evaporation.

Nanoconfined Water‐Molecule Channels for High‐Yield Solar Vapor Generation under Weaker Sunlight

“…[ 1–3 ] Due to the high effective solar‐to‐vapor conversion, the interfacial solar vapor generation (SVG) process has caused extensive attention throughout the past few years. [ 4–25 ] To achieve rapid SVG under irradiation, many broadband light absorbers have been developed, including plasmonic metal nanoparticles, [ 6–8 ] carbon‐based materials, [ 9–13 ] semi‐conductor materials [ 14–17 ] and polymers. [ 18,19 ] However, in the case of merely solar energy input, the SVG rate will be theoretically limited at 1.47 kg m −2 h −1 under 1 sun irradiation (1 kW m −2 , assuming 100% energy conversion efficiency) due to the latent heat requirement for water vaporization.…”

“…To achieve higher vapor yields, one of the most effective methods is assisting water molecules to evaporate as clusters by optimizing the structure of absorbers, which can reduce the water vaporization enthalpy. [ 21–26 ] At present, the world‐record SVG rate under 1 sun was 4.0 kg m −2 h −1 , which was achieved in a hydrophilic hydrogel evaporator with hydrophobic island‐shaped patches. [ 25 ] Unfortunately, affected by seasons or regions, the outdoor sunlight intensity is usually far lower than 1 sun, [ 10,17,23,27 ] and the reported evaporators showed much lower vapor yields under weaker natural sunlight conditions.…”

“…[ 21–26 ] At present, the world‐record SVG rate under 1 sun was 4.0 kg m −2 h −1 , which was achieved in a hydrophilic hydrogel evaporator with hydrophobic island‐shaped patches. [ 25 ] Unfortunately, affected by seasons or regions, the outdoor sunlight intensity is usually far lower than 1 sun, [ 10,17,23,27 ] and the reported evaporators showed much lower vapor yields under weaker natural sunlight conditions. [ 17,19,23 ] Thus developing evaporators with high vapor yields under weaker solar irradiations is expected for practical applications.…”

“…[ 17,19,23 ] Thus developing evaporators with high vapor yields under weaker solar irradiations is expected for practical applications. Meanwhile, the fundamental evaporation mechanisms at the evaporator interface have rarely been studied, [ 25 ] which will conduct the reasonable design of the evaporator structure with high SVG performance.…”

“…[20] To achieve higher vapor yields, one of the most effective methods is assisting water molecules to evaporate as clusters by optimizing the structure of absorbers, which can reduce the water vaporization enthalpy. [21][22][23][24][25][26] At present, the 2H-MoS 2 structure (JCPDS No. 37-1492), the interlayer spacing of the 1D-OMoSNSA enlarged from 0.615 to 0.98 nm, corresponding to the shift of (002) diffraction peak.…”